Error fetching data for this visual

Hi, SharpPoint 

In your description, some users can see the data normally, while some users will get an error, do the users who can see the data normally have a role in the workspace? For example Admin, Contributor, Member, Viewer, is there any difference in the permissions of these users?

And what connection mode are you using to connect to the data source?QirectQuery?Or Live Connection?

The error message you provided shows ‘authentication’:null, which could mean that the authentication information is missing or incorrectly configured. Please ensure that the user has the appropriate permissions for access and that authentication is configured correctly.

If you are using Live Connection, you need to use Map User when creating a gateway connection:

Here's the official documentation, hope it helps:

Manage SQL Server Analysis Services data sources - Power BI | Microsoft Learn

I hope my suggestions give you good ideas, if you have any more questions, please clarify in a follow-up reply.
Best Regards,
Fen Ling,
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